328 research outputs found

    Anàlisi espacio-temporal de la línia de costa i del foredune del sistema dunar de Sa Canova d’Artà (Mallorca)

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    [cat] Els sistemes platja-duna, són una de les morfologies sedimentàries més abundants a les Illes Balears. Aquests es troben composats per diferents subsistemes, els quals presenten diferents nivells de dinamisme. Des d’aquest punt de vista, la foredune és el sector més dinàmic de la part emergida del sistema i en la qual la vegetació té un paper clau per al desenvolupament de la resta del sistema. Tots i cada un dels sistemes existents a la comunitat autònoma i a la resta del món disposa d’una condicions/característiques que el fan peculiar i diferent a la resta; a part de les pròpies condicions físiques intrínseques al propi medi, a dia d’avui els sistemes han de fer front a tota una sèrie de pressions d’origen antròpic, destacant especialment l’activitat turística en el cas Balear. El cas d’estudi, és Sa Canova, situada al terme municipal d’Artà (NE de l’illa de Mallorca); aquest sistema tampoc n’és una excepció, al llarg del període d’estudi (1956-2012), ha sofert variacions, tant d’origen natural, com antròpic, les quals han tingut com a conseqüència el sistema dunar actualment existent.[eng] The beach-dune systems, are one of the most abundant sedimentary morphologies in the Balearic Islands. These are composed of different subsystems, which present different levels of dynamism. From this point of view, Foredune is the most dynamic sector of the emerging part of the system and in which vegetation plays a key role for the development of the rest of the system. Each and every one of the existing systems in the autonomous community and the rest of the world has conditions / characteristics that make it peculiar and different from the rest; Apart from the intrinsic physical conditions inherent in their own environment, today, systems have to deal with a whole series of pressures of anthropogenic origin, with special emphasis on tourism in the Balearic Islands. The case study is Sa Canova, located in the municipality of Artà (NE of the island of Mallorca); This system is not an exception either, during the period of study (1956-2012), it has undergone variations, both of natural origin and anthropic, which have resulted in the current dune system

    Morfogènesi i dinàmica de la platja des Codolar (Eivissa, Illes Balears)

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    S'ha analitzat la textura dels còdols de la platja des Codolar, Eivissa, a partir del mostreig de quatre seccions de la platja. A cada secció s’han pres mostres de la berma superior i de la inferior, totalitzant el mesurament de 400 còdols. S'han analitzat la distribució dels còdols, la seva mida i la seva classificació. La forma dels còdols s’ha parametritzat a partir del diagrama de Zingg, l'índex d’Arrodoniment de Wadell, la màxima projecció de Esfericitat i l'índex Oblat-Prolat. El resultat mostra una clara gradació de sud-est a nord-oest tant en la grandària com en el arrodoniment i la esfericitat dels còdols. Això en indica clarament que la seva font d'alimentació són els despreniments del cap Falcó, i que el seu transport es produeix per deriva litoral envers el nord-oest. El resultat és la formació d'una barra litoral que fins i tot presenta formes atribuïbles a ventalls d’overwash, que juntament amb ventalls al·luvials delimiten una zona humida, que a l'actualitat ocupen les Salines d'Eivissa.The texture of the Es Codolar gravel beach, South of Ibiza, was analyzed from samples in four sections of the beach. In each section two samples have been taken: one from the upper berm and another from the lower one. A total of 400 pebbles and cobbles were measured. The distribution of shingles, their grain size and sorting have been analyzed. Shingle shape has been parameterized trough the Zingg diagram, the Wadell roundness index, the maximum projection of sphericity and the Oblate-Prolate Index. The results show a clear gradient both in grain size, roundness and the shingles sphericity from Southeast to Northwest. This clearly indicates that the source of sediment supply are located at Cap Falcó detachments, Transport is produced by long shore drift towards the Northwest and he result is the formation of a shingle barrier that closes a wetland that nowadays currently occupy by the Salinas of Ibiza

    Gestión de entregables con grupos grandes

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    En el Espacio Europeo de Educación Superior (EEES), el docente debe asumir la responsabilidad de planificar el trabajo que tiene que realizar el estudiante, tanto dentro como fuera del aula, y además, evaluar el trabajo realizado, preferentemente de forma continua. Para ello, el profesor puede optar por preparar un conjunto de documentos donde se expliciten las actividades que el estudiante debe realizar a lo largo del curso y que irá entregando para su corrección (en adelante, llamaremos entregables a dichos documentos). El problema que plantea la utilización de entregables es que su gestión es un proceso bastante costoso, especialmente cuando el número de estudiantes por grupo es elevado. En este artículo se presenta una aplicación de gestión de entregables que reduce notablemente el tiempo que el profesor debe dedicar a su gestión, permitiendo que sea posible utilizar entregables incluso con grupos grandes. Se propone también un método de evaluación en el que el porcentaje de entregables realizados por el estudiante forma parte de su evaluación. Tanto la aplicación de gestión como el método de evaluación propuestos han sido probados en varias asignaturas con resultados satisfactorios.Este proyecto docente ha sido financiado por la Unitat de Suport Educatiu de la Universidad Jaume I (código del proyecto: 05G073-400)

    Aplicación para la gestión y calificación de actividades ECTS

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    En este artículo se describe una aplicación web que facilita la gestión y calificación de las actividades ECTS realizadas por los estudiantes. La principal ventaja de esta aplicación es que permite el seguimiento continuado del trabajo realizado por los estudiantes, aún con grupos grandes. La aplicación está siendo utilizada actualmente en 9 asignaturas del Grado en Ingeniería Informática de la Universidad Jaume I, gestionando más de 200 actividades diferentes por curso.This paper describes a web application that facilitates the management and assesment of the ECTS activities performed by students. The main advantage of this application is that it allows the continuous monitoring of the work performed by students, even with big groups. The application is currently being used in 9 courses of the degree in Computer Engineering at the Jaume I University, managing more than 200 different activities per course.Este trabajo ha sido parcialmente financiado por la Unitat de Suport Educatiu de la Universidad Jaume I, en el marco del Proyecto de Innovación Educativa 10G136-329

    Advanced Virgo Plus: Future Perspectives

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    While completing the commissioning phase to prepare the Virgo interferometer for the next joint Observation Run (O4), the Virgo collaboration is also finalizing the design of the next upgrades to the detector to be employed in the following Observation Run (O5). The major upgrade will concern decreasing the thermal noise limit, which will imply using very large test masses and increased laser beam size. But this will not be the only upgrade to be implemented in the break between the O4 and O5 observation runs to increase the Virgo detector strain sensitivity. The paper will cover the challenges linked to this upgrade and implications on the detector's reach and observational potential, reflecting the talk given at 12th Cosmic Ray International Seminar - CRIS 2022 held in September 2022 in Napoli

    Quantum Backaction on kg-Scale Mirrors: Observation of Radiation Pressure Noise in the Advanced Virgo Detector

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    The quantum radiation pressure and the quantum shot noise in laser-interferometric gravitational wave detectors constitute a macroscopic manifestation of the Heisenberg inequality. If quantum shot noise can be easily observed, the observation of quantum radiation pressure noise has been elusive, so far, due to the technical noise competing with quantum effects. Here, we discuss the evidence of quantum radiation pressure noise in the Advanced Virgo gravitational wave detector. In our experiment, we inject squeezed vacuum states of light into the interferometer in order to manipulate the quantum backaction on the 42 kg mirrors and observe the corresponding quantum noise driven displacement at frequencies between 30 and 70 Hz. The experimental data, obtained in various interferometer configurations, is tested against the Advanced Virgo detector quantum noise model which confirmed the measured magnitude of quantum radiation pressure noise

    The Advanced Virgo+ status

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    The gravitational wave detector Advanced Virgo+ is currently in the commissioning phase in view of the fourth Observing Run (O4). The major upgrades with respect to the Advanced Virgo configuration are the implementation of an additional recycling cavity, the Signal Recycling cavity (SRC), at the output of the interferometer to broaden the sensitivity band and the Frequency Dependent Squeezing (FDS) to reduce quantum noise at all frequencies. The main difference of the Advanced Virgo + detector with respect to the LIGO detectors is the presence of marginally stable recycling cavities, with respect to the stable recycling cavities present in the LIGO detectors, which increases the difficulties in controlling the interferometer in presence of defects (both thermal and cold defects). This work will focus on the interferometer commissioning, highlighting the control challenges to maintain the detector in the working point which maximizes the sensitivity and the duty cycle for scientific data taking

    Virgo Detector Characterization and Data Quality during the O3 run

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    The Advanced Virgo detector has contributed with its data to the rapid growth of the number of detected gravitational-wave signals in the past few years, alongside the two LIGO instruments. First, during the last month of the Observation Run 2 (O2) in August 2017 (with, most notably, the compact binary mergers GW170814 and GW170817) and then during the full Observation Run 3 (O3): an 11 months data taking period, between April 2019 and March 2020, that led to the addition of about 80 events to the catalog of transient gravitational-wave sources maintained by LIGO, Virgo and KAGRA. These discoveries and the manifold exploitation of the detected waveforms require an accurate characterization of the quality of the data, such as continuous study and monitoring of the detector noise. These activities, collectively named {\em detector characterization} or {\em DetChar}, span the whole workflow of the Virgo data, from the instrument front-end to the final analysis. They are described in details in the following article, with a focus on the associated tools, the results achieved by the Virgo DetChar group during the O3 run and the main prospects for future data-taking periods with an improved detector.Comment: 86 pages, 33 figures. This paper has been divided into two articles which supercede it and have been posted to arXiv on October 2022. Please use these new preprints as references: arXiv:2210.15634 (tools and methods) and arXiv:2210.15633 (results from the O3 run
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